Answer:
To strengthen trade regulation.
Explanation:
Prior to the implementation of central currency, confusion often happen among traders from different regions' of Umayyad region. Different regions implemented different medium of transaction that often resulted in unfairness during the trade.
To deal with this, Umayyad empire created a central currency that Must be used by all traders within Umayyad territory. This made it easier for transaction to be valued and improve the trades in Umayyad empire.
